hey everyone, i'm new to the blazer world, i have a 73 K5 with a crate motor, 3" body lift, 3" susp. lift and 33" super swampers. one of my questions is this: what are teh vacuum lines for that are attached to the differential housings for? when i bought mine, the front one was broken off and hanging. also, how much power goes to the front wheels when the transfer case is engaged? i ask because i was driving on the beach in mexico and got stuck because the front wheels weren't pulling even though i had the t case engaged. my rears were spinning but the fronts were just sitting there. also, what kind of diffs are in my truck front and rear? i read that dana 44 is in the front but waht's in the back? thanks.